Interface comprising a rolling nasal bridge portion

ABSTRACT

An interface for positive pressure therapy includes a mask assembly, a headgear assembly and a connection port assembly. The mask assembly comprises a seal member that has an upper portion movably connected to an integrated lower portion, wherein the upper portion rolls during hinging movement of the upper portion relative to the lower portion. The headgear assembly allows connection to the mask assembly in a direction substantially normal to a direction of strap tension. The connection port assembly includes a swivel elbow with a valve member that controls flow through a port that opens toward the user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of PCT InternationalApplication Number PCT/IB2012/000858, filed Apr. 13, 2012, which claimspriority to U.S. Provisional Patent Application No. 61/476,188, filedApr. 15, 2011, U.S. Provisional Patent Application No. 61/504,295, filedJul. 4, 2011 and U.S. Provisional Patent Application No. 61/553,067,filed Oct. 28, 2011, each of which is hereby incorporated by referencein its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to face masks that cover atleast one of a nose and a mouth of a user to supply respiratory gasunder positive pressure. More particularly, certain aspects of thepresent invention relate to such masks that have a nasal bridge sealportion that moves relative to another seal portion of the mask.

Description of the Related Art

Face masks can be used to provide respiratory gases to a user underpositive pressure. In configurations in which both a mouth and a nose ofa user are covered, the full face mask typically will overlie a bridgeof the nose. Generally, a single seal will circumscribe the nose and themouth of the user.

Such full face masks commonly are secured to a head of the user withheadgear. In order to sufficiently reduce leakage, the headgeartypically is tightened, which results in an elevated pressure beingexerted on a bridge of a user's nose. In other words, as the headgear istightened, the silicone seal typically applies a progressivelyincreasing load on the bridge of the nose. The pressure can be a sourceof discomfort and, in some circumstances, can lead to pressure soresover time.

SUMMARY OF THE INVENTION

It is an object of the present disclosure to provide one or moreconstructions and/or methods that will at least go some way towardsimproving on the above or that will at least provide the public or themedical profession with a useful choice.

Accordingly, an interface is provided for use in providing positivepressure respiratory therapy. The interface comprises a mask assembly.The mask assembly comprises a mask seal and a mask base that isremovably connected to the mask seal. The mask seal comprises a maskseal clip that is more rigid than at least a portion of the mask seal.The mask seal clip is generally cup-shaped in configuration with an openproximal end and a generally closed distal end. A generally pentagonallip extends around the proximal end. The mask seal clip comprises anarcuate upper portion with an outer surface. A mask seal clip arc lengthis defined along the outer surface adjacent an upper extremity of theupper portion between a pair of hinge points. A hinge axis extendslaterally across the mask assembly between the hinge points and at leasta portion of the upper portion of the mask seal clip is positionedvertically higher than the hinge axis. The mask seal clip upper portioncomprises a support surface. A generally central passage extends throughthe mask clip into a chamber defined by the mask seal. The mask sealcomprises a flexible upper portion that is configured to be positionedover a nasal region of a user. The mask seal upper portion is positionedvertically higher than the hinge axis. The mask seal upper portioncomprises a region of reduced stiffness located between two regions ofincreased stiffness. The region of reduced stiffness is capable ofrolling to allow pivoting of the mask seal upper portion relative to themask seal clip. One of the two regions of increased stiffness ispositioned adjacent to a small radius bend and the other of the tworegions of increased stiffness is position adjacent to a reinforcingcomponent. The small radius bend and the reinforcing component defineboundaries between which the upper portion of the mask exhibits rollingduring pivoting of the upper portion about the pivot axis. The mask sealupper portion has a first curve length adjacent to the small radius bendand a second curve length adjacent to the reinforcing band. The firstcurve length can be smaller than the second curve length. The curvelength increases as a measured location moves away from the mask sealclip. The mask base overlies at least a portion of the mask seal clip.The mask base comprises a first pocket and a second pocket. The firstand second pockets are positioned symmetrically relative to a centerplane that substantially bisects the mask base. Each of the first pocketand the second pocket comprises a vertical dimension that is larger thana transverse dimension. The mask base also comprises a wall that definesa central opening. The wall extends into the generally central passageof the mask seal clip. A connection port assembly comprises an elbowterminating in a ball shaped member. The ball shaped member is sized andconfigured to be held by the wall that defines the central opening. Theconnection port assembly also comprises a removable swivel member. Theremovable swivel member is secured by a lever. The lever overlies aport. The port is selectively coverable with a flap. The flap also iscapable of closing a central passage within the elbow. The port openingis in a general direction of the mask when the elbow is connected to themask. A headgear assembly comprises a pair of upper straps and a pair oflower straps. One of the pair of upper straps and one of the pair oflower straps is connected to a first clip. Another of the pair of upperstraps and another of the pair of lower straps is connected to a secondclip. The first clip and the second clip are securable within thepockets of the mask base such that the clips are brought into engagementwithin the pockets by moving in a direction substantially normal to astrap tensile force direction.

In some configurations, the mask seal is a full face mask.

In some configurations, the mask seal clip is integrated into the maskseal such that the mask seal clip is non-separable from the mask seal.

In some configurations, the mask base is removably connected to the maskseal.

In some configurations, an outer surface of the upper portion rolls ontothe support surface of the mask seal clip and the support surfacedefines an outer surface of the upper portion of the mask seal clip.

In some configurations, the region of reduced stiffness comprises aregion of reduced thickness compared to the regions of increasedstiffness.

In some configurations, the upper portion of the mask seal comprises anapex defined by a first wall and a second wall and the reinforcingcomponent extends along at least a portion of the first wall and alongat least a portion of the second wall. Preferably, the reinforcingcomponent extends over the apex of the upper portion of the mask seal.

In some configurations, the reinforcing component ends at both ends in alocation generally vertically higher than the hinge points.

A mask assembly can comprise a mask seal. The mask seal comprises anupper portion and a lower portion. The upper portion is pivotablerelative to the lower portion. The upper portion comprises a region ofreduced stiffness that is positioned between a first boundary and asecond boundary. The first boundary is defined by a stiffness greaterthan that in the region of reduced stiffness. The second boundary isdefined by a stiffness greater than that in the region of reducedstiffness. When the first boundary is moved toward the second boundary,the region of reduced stiffness buckles in a single direction to definea roll of material that changes in size as the first boundary continuesto move toward the second boundary.

In some configurations, the region of reduced stiffness facilitatesmovement of the upper portion of the seal member relative to the lowerportion of the seal member. Preferably, the upper portion comprises anasal bridge portion of the mask and movement of the first boundarytoward the second boundary facilitates movement of the nasal bridgeportion of the mask relative to the lower portion of the mask.

In some configurations, the second boundary is positioned between theupper portion and the lower portion. Preferably, the mask furthercomprises a mask seal clip that has an increased rigidity relative tothe mask seal and the second boundary is positioned along an end of themask seal clip. More preferably, the roll of material overlies at leasta portion of the mask seal clip.

In some configurations, the first boundary is defined along areinforcing component. Preferably, the reinforcing component comprises aplastic band.

In some configurations, the region of reduced stiffness is defined witha reduced thickness relative to the first boundary.

In some configurations, the second boundary is defined by a cornerhaving a small radius.

In some configurations, the roll extends over at least a portion of themask seal.

In some configurations, the roll overlies at least a portion of the maskseal clip when the first boundary is moved fully toward the secondboundary.

A mask assembly can comprise a mask seal. The mask seal comprises anasal region and an oral region. The nasal region and the oral regionare integrally formed. The nasal region is movable relative to the oralregion such that forces exerted by the nasal region in multiplepositions remain substantially constant while forces exerted by the oralregion increase.

A mask assembly comprises a mask seal connected to a headgear assembly.The mask seal is configured to encircle a nasal bridge region and anoral region of a user. The mask seal comprises nonpleated means forapplying a substantially constant force to the nasal bridge region whileapplying increasing forces to an oral region when the headgear assemblyis tightened.

A mask assembly comprises a seal. The seal comprises a flange thatengages a face of a user. The seal is removably connected to a maskbase. The mask base comprises a first opening and a second opening. Thefirst opening and the second opening receive a first clip and a secondclip from an associated headgear assembly. The mask base furthercomprises a passageway positioned generally between the first openingand the second opening. The passageway is adapted to receive a breathingtube connector.

In some configurations, the mask assembly further comprises a mask sealclip that is connected to the mask seal and that is removably connectedto the mask base. Preferably, the mask base overlies a substantialportion of the mask seal clip. More preferably, the mask base comprisesa peripheral edge and at least one recess is defined along theperipheral edge of the mask base at a location that overlies the maskseal clip.

A mask assembly comprises a mask seal. The mask seal comprises aproximal flange adapted to contact a face of a user. The mask sealcomprises a distal facing surface. A mask base comprises a peripheraledge and a cover surface extends from the peripheral edge. The mask basecover surface overlies at least a portion of the distal facing surfaceof the mask seal such that the mask base cover surface is spaced apartin a distal direction from the mask seal distal facing surface wherebythe mask base cover surface and the mask seal distal facing surfaceprovide an insulating effect to the mask assembly that reduces humidityrainout.

A headgear assembly is configured to secure a mask assembly to a user'shead. The headgear assembly comprises a strap assembly. The strapassembly comprises a rear, upper and lower arms, and at least one crownarm. The upper and lower arms define arcuate regions shaped to at leastpartially encircle a user's ears. A soft edging is attached to at leasta portion of a periphery of the strap assembly.

In some configurations, the strap assembly comprises a semi-rigid strapand the soft edging is butt-joined to the semi-rigid strap withoutoverlapping the semi-rigid strap. In some configurations, the semi-rigidstrap comprises a first thickness and the soft edging comprising asecond thickness with the first thickness and the second thickness beingsubstantially the same. In some configurations, the semi-rigid strapcomprising a thickness and the soft edging is thinner than the thicknessin at least one region. In some configurations, the semi-rigid strapcomprises a thickness and the soft edging is thicker than the thicknessin at least one region. In some configurations, the soft edging forms abulbous end to the semi-rigid strap.

A clip assembly is configured to secure headgear to a mask assembly. Theclip assembly comprises an outer cover and an inner catch. The innercatch is configured to attach to the outer cover thereby holding ontoone or more straps from a headgear assembly. The inner catch comprisesan elongated slot and a circular opening. The elongated slot can extendalong an elongate axis and can have a width transverse to the elongateaxis. The circular opening can have a diameter larger than the width.The elongate axis extends along a direction transverse to the strapswhen attached to the outer cover and the inner catch.

An elbow assembly is configured to connect a mask assembly to an airconduit. The elbow assembly comprises an elbow. The elbow comprisesinner and outer walls and defines an air flow channel therebetween. Theinner wall comprises a port on a side of the elbow. A sleeve is coupledwith the elbow. The sleeve comprises a flap. When the flap is at a firstposition, the flap at least partially blocks the port and allows gasfrom the air conduit to pass to a user via the elbow and, when the flapis at a second position, the flap at least partially blocks the airconduit thereby allowing gas to flow from the user to a location outsideof the sleeve via the port and air flow channel. The air flow channelcan direct air away from the side of the elbow.

In some configurations, the air flow channel comprises two air flowchannels. In some configurations, the sleeve further comprises a bumpextending around an outer surface of the sleeve and a recess adjacent tothe bump. In some arrangements, the bump and the recess are adapted toreceive a swiveling component incorporating a ridge to engage with thebump.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of embodiments of thepresent invention will be described with reference to the followingdrawings.

FIG. 1 is front view of a user wearing an interface that is arranged andconfigured in accordance with certain features, aspects and advantagesof the present invention.

FIG. 2 is a side view of a user wearing the interface of FIG. 1.

FIG. 3 is a perspective view of a mask seal and mask seal clip of theinterface of FIG. 1.

FIG. 4 is a side view of the mask seal and mask seal clip of FIG. 3.

FIG. 5 is a rear perspective view of the mask seal clip of FIG. 3.

FIG. 6 is a rear elevation view of the mask seal clip of FIG. 3.

FIG. 7 is a side elevation view of the mask seal clip of FIG. 3.

FIG. 8 is a top plan view of the mask seal clip of FIG. 3.

FIG. 9 is a front elevation view of the mask seal and mask seal clip ofFIG. 3.

FIG. 10 is a rear elevation view of the mask seal and mask seal clip ofFIG. 3.

FIG. 11 is a side elevation view of the mask seal and mask seal clip ofFIG. 3.

FIG. 12 is an enlarged section view of a portion of the mask seal andmask seal clip of FIG. 3.

FIG. 13 is a front perspective view of the mask seal, mask seal clip andmask base of the interface of FIG. 1.

FIG. 14 is a section view of the mask seal, mask seal clip and mask baseof FIG. 13.

FIG. 15 is a side elevation view of the mask seal, mask seal clip andmask base of FIG. 13.

FIG. 16 is a top plan view of the mask seal, mask seal clip and maskbase of FIG. 13.

FIG. 17 is a perspective view of the connection port assembly of FIG. 1.

FIG. 18 is a side elevation view of the connection port assembly of FIG.17.

FIG. 19 is a rear elevation view of the connection port assembly of FIG.17.

FIG. 20 is a sectioned side elevation view of the connection portassembly of FIG. 17.

FIG. 21 is a sectioned perspective view of the connection port assemblyof FIG. 17.

FIG. 22 is a perspective view of the clip assembly of FIG. 1.

FIG. 23 is a sectioned view of the clip assembly of FIG. 22.

FIG. 24 is a sectioned view similar to the sectioned view of FIG. 12showing a mask seal configured to roll under a portion of a mask sealclip 112.

FIG. 25 is a sectioned view similar to the sectioned view of FIG. 14,wherein the mask seal clip has a reduced dimension.

FIG. 26 is a sectioned view similar to the sectioned view of FIG. 14,wherein the mask seal clip is omitted.

FIG. 27 is a further sectioned view similar to the sectioned view ofFIG. 14, wherein the mask seal clip is omitted.

FIG. 28 is a graphical depiction illustrating a relationship betweenload (or force) on a user's body as a function of mask extension.

FIG. 29 is a perspective view a backbone compatible with the headgearassembly of FIGS. 1 and 2.

FIG. 30 is an enlarged view of the end region of a lower arm of FIG. 29.

FIG. 31 is an enlarged cross-sectional view of the end region of FIG.30.

FIG. 32 is a perspective view of a mask assembly comprising a mask,clips, and straps.

FIG. 33 is a side view of one of the two clips of FIG. 32.

FIG. 34 is an exploded view of the clip of FIG. 33.

FIG. 35 is a top view of the inner catch of the clip of FIG. 33.

FIG. 36 is a front view of a mask base having two mounting posts, andone inner catch of a clip mounted to the left mounting post.

FIG. 37 is a front view of another configuration of a mask base havingtwo mounting posts, and another configuration of a clip mounted to themask base's left mounting post.

FIGS. 38-47 are additional configurations of clips and associated masksand mounting posts.

FIG. 48 is a side view of another configuration of a swivel assembly.

FIG. 49 is an exploded view of the swivel assembly of FIG. 48.

FIG. 50 is a cross-sectional view taken along line 50-50 of FIG. 48.

FIG. 51 is a cross-sectional view taken along line 51-51 of FIG. 48.

FIG. 52 is a side view of the backbone of FIG. 29 attached to a user'shead.

FIG. 53 is a rear perspective view of the backbone of FIG. 29 attachedto a user's head.

FIG. 54 is a perspective view of a flexible headgear with a panel foruse with a mask assembly in the field of respiratory therapy.

FIG. 55 is a view of an enlarged end enlarged region of arms of FIG. 54with an embedded hook-fabric tab attached thereto.

FIG. 56 is a perspective view of the end region of FIG. 55.

FIG. 57A is a rear view of a headgear without a panel attached to atesting model before a force is applied to lower arms of the headgear.

FIG. 57B is a rear view of the headgear of FIG. 57A illustrating thedisplacement of a back strap portion of the headgear when a force isapplied to the lower arms of the headgear.

FIGS. 58A-58D are alternate configurations of panels compatible for usewith the headgear of FIG. 54.

FIG. 59 is an assembly incorporating headgear with a winged buckleconnection.

FIG. 60 is a portion of the headgear having the winged buckleconnection.

FIG. 61 is a top view of a winged buckle used in the winged buckleconnection of FIG. 59.

FIG. 62 is a side view of the winged buckle used in the winged buckleconnection of FIG. 59.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference initially to FIGS. 1 and 2, an interface 100 is shown inposition on a user U. The interface 100 comprises an interface that canbe used in the field of respiratory therapy. The interface 100 hasparticular utility with forms of positive pressure respiratory therapy.For example, the interface 100 can be used for administering continuouspositive airway pressure (“CPAP”) treatments. In addition, the interface100 can be used with variable positive airway pressure (“VPAP”)treatments and bi-level positive airway pressure (“BiPAP”) treatments.The interface can be used with any suitable CPAP system.

The interface 100 can comprise any suitable mask configuration. Forexample, certain features, aspects and advantages of the presentinvention can find utility with nasal masks, full face masks, oronasalmasks or any other positive pressure mask. The illustrated mask is afull face mask. The illustrated interface 100 generally comprises a maskassembly 102, a connection port assembly 104 and a headgear assembly106.

With reference to FIG. 13, the mask assembly 102 generally comprises amask seal 110, which can include a mask seal clip 112, and a mask base114. As will be described, the mask seal clip 112 preferably connectsthe mask seal 110 to the mask base 114. While the illustrated mask seal110 and mask seal clip 112 are formed separately and secured together,in some configurations, the mask seal 110 and the mask seal clip 112 canbe integrated into a single component. In some configurations, the maskseal 110 is overmolded onto the mask seal clip 112.

With reference to FIG. 3, the mask seal clip 112 is relatively morerigid, stiffer or more inflexible than the mask seal 110. In someconfigurations, the mask seal clip 112 is formed of a polycarbonatematerial. In some configurations, at least a portion of the mask sealclip 112 is formed of a polycarbonate or other rigid or semi-rigidmaterial. In some configurations, the mask seal clip 112 is formed atleast partially of silicone or another suitable material. In suchconfigurations, at least the silicone portion of the mask seal clip 112may be formed to be relatively thicker compared to the more flexibleportions of the mask seal 110. The mask seal clip 112 providesstructural support to the mask seal 110 in the illustratedconfiguration.

As shown in FIG. 14, the mask seal clip 112 can define a large portionof the mask assembly 102. As shown, the illustrated mask base 114overlies a significant portion of the mask seal clip 112. With referenceto FIGS. 25-27, the mask assembly 102 can be configured with differingconstructions, as desired. For example, with reference to FIG. 25, themask seal clip 112 extends a limited amount from the interface with themask seal 110. In the configuration illustrated in FIG. 25, the maskbase 114 overlies at least a portion of the mask seal clip 112 while themask seal clip 112 defines a very limited rim-shaped configuration abouta portion of the mask seal 110. With reference to FIG. 26, the mask sealclip is omitted in its entirety and the mask seal 110 is overmoldeddirectly onto the mask base 114. In some configurations, however, themask seal 110 and the mask base 114 can be configured such that the twocomponents can be separated. For example, as shown in FIG. 27, the maskseal 110 can comprise a peripheral flange 111 while the mask base 114can comprise a peripheral channel 115 that receives the peripheralflange 111 such that the mask seal 110 can be removably secured to themask base 114. In some configurations, other suitable manners can beused to secure the mask seal 110 to the mask base 114. Moreover, whilethe illustrated configuration of FIG. 27 shows an embodiment without amask seal clip 112, the mask seal clip 112 and the mask base 114 havebeen combined into the mask base 114.

With reference to FIG. 5, the illustrated mask seal clip 112 comprises asubstantially cup-shaped configuration. A proximal end 120 defines anopen end of the illustrated mask seal clip 112 while a distal end 122defines a generally closed end of the illustrated mask seal clip 112. Inthe illustrated configuration, the proximal end 120 is generallycircumscribed by a lip 124. The lip 124 is generally pentagonal whenviewed from the back (see FIG. 5). As shown in FIG. 7, a wall 126generally sweeps forward in an arcuate manner. The arcuate shape to thewall 126 provides a three dimensional configuration to the illustratedmask seal clip 112.

With continued reference to FIG. 7, an upper portion 130 of theillustrated mask seal clip 112 is generally arcuate in configuration. Inaddition, the generally arcuate configuration of the illustrated maskseal clip 112 is configured to accommodate larger noses while notextending upward over the nose to as great an extend as the mask seal110, as shown in FIGS. 1 and 2.

With initial reference to FIG. 3, the upper portion 130 of theillustrated mask seal clip 112 preferably comprises two arcuatedimensions. First, an arc length 132 can be defined along an upperextremity of the upper portion 130 of the illustrated mask seal clip112. The arc length 132 can be defined between inflection points 134found along a perimeter of the illustrated mask seal clip 112.

As shown in FIG. 7, the upper portion 130 of the illustrated mask sealclip 112 also comprises a side profile radius 136. As shown, the upperportion 130 can have a slightly increasing side profile radius 136 suchthat the radius increases slightly as a distance from the upper endincreases. In some configurations, the upper portion 130 can comprise asubstantially constant side profile radius 136 or a decreasing sideprofile radius. Advantageously, the slightly increasing side profileradius 136 provides an increased volume in the mask 100 proximate theuser's nose.

With reference to FIG. 3 and FIG. 6, the mask seal clip 112 preferablycomprises at least two recesses 140. In the illustrated configuration,the mask seal clip 112 comprises two recesses 140 that are disposed ontwo lateral sides of a generally vertical center plane CP (see FIG. 6).The generally vertical center plane CP preferably corresponds to amid-sagittal plane of the user and splits the illustrated mask seal clip112 into substantially mirror image halves. The two recesses 140 definetwo generally enclosed pockets in the illustrated mask seal clip 112.The illustrated recesses 140 comprise further recesses 142 that are usedto provide adequate clearance for reasons that will be discussed belowwhile limiting an amount of encroachment into a nasal region of achamber defined by the mask assembly 102.

The illustrated mask seal also comprises a generally central passage 144that is defined by a wall 146. In the illustrated configuration, thewall 146 generally encloses the passage 144. Preferably, the wall 146 isgenerally cylindrical in configuration and extends through the wall 126.Other configurations are possible.

With reference to FIG. 14, the mask seal 110 comprises a flexibleportion that extends away from the proximal end 120 of the mask sealclip 112. In the illustrated configuration, the mask seal 110 isovermolded onto the mask seal clip 112 such that the mask seal 110 andthe mask seal clip 112 combine to form an integrated and preferablynon-separable assembly. In some configurations, attempts to separate themask seal 110 and the mask seal clip 112 result in the destruction ofthe interface between the components and/or destruction of one or bothof the mask seal 110 and the mask seal clip 112. As described above,other assemblies also can be used to connect the mask seal clip 112 tothe mask seal 110. The illustrated configuration, however,advantageously results in a construction that is easy to clean andmaintain.

With reference to FIG. 4, the mask seal clip 112 preferably is arrangedsuch that it is generally flush with an inner rim 150 of the mask seal110. In the illustrated configuration, the mask seal 110 comprises arelatively small radius portion 152 that joins an upper portion 154. Theupper portion 154 of the mask seal 110 is configured to extend over anasal region of the user. In some configurations, the upper portion 154is configured to extend over a nasal bridge region of the user U.

The upper portion 154 is connected with a lower portion 156 of the sealmember 110. The lower portion 156 extends laterally outward from themask seal clip 112 as shown in FIG. 9. In addition, the lower portion156 wraps rearward and inward, as shown in FIGS. 4 and 10 respectively.Together, on a proximal side of the full face mask assembly 102, theupper portion 154 and the lower portion 156 combine to define a facecontacting flange 160, which is shown in FIG. 10. The face contactingflange 160 is configured to underlie a lower lip of the user, extendalong the outside of the mouth, extend upward along the cheekbones andextend across the bridge of the nose of the user. Thus, the illustratedface contacting flange 160 defines a generally tear-drop shaped opening162. When the mask assembly 102 is seated on the face of the user, theflange 160 will lie flat over the bridge of the nose, the cheekbones,the outside of the mouth and below the lower lip of the user. With asupply of positive pressure air, the mask seal 110 will balloon and sealagainst the face of the user to reduce or eliminate the likelihood ofleakage between the flange 160 and the face of the user.

As shown by the dashed lines in FIG. 11, the upper portion 154 of themask seal 110 is designed to roll over onto an outer surface 170 of themask assembly 102. In the illustrated configuration, the outer surfaceof the mask seal 110 smoothly rolls into abutment with the outer surfaceof the mask seal clip 112 such that the outer surface of the mask sealclip 112 forms a support surface. In some configurations, the outersurface 170 onto which the upper portion 154 rolls comprises at least aportion of the outer surface of the mask seal clip 112. In someconfigurations, the outer surface 170 onto which the upper portion 154rolls comprises almost exclusively the outer surface of the mask sealclip 112. In some configurations, the upper portion 154 rolls ontoanother portion of the mask seal 110. In some configurations, the upperportion 154 rolls onto the mask seal base 114.

With reference to FIG. 12, to assist with the rolling of the upperportion 154, the upper portion 154 can have a varying thickness or avarying stiffness. In the configuration shown in FIG. 12, the upperportion 154 comprises a thick/thin/thick configuration. In other words,to induce the upper portion 154 to roll in a region between the facecontacting flange 160 and the small radius 152 proximate the mask sealclip 112, a reduced stiffness region 172 can be incorporated. In theillustrated configuration, the reduced stiffness region 172 isincorporated into the mask seal 110. The reduced stiffness region 172reduces or eliminates the likelihood of the mask seal 110 buckling oradversely deforming in a region other than the desired region forrolling.

While the illustrated configuration uses a region of reduced thickness,other means for providing the reduced stiffness region 172 also can beused to induce rolling of the seal member 110. For example, the materialof the seal member 110 can be configured to have a reduced stiffnessthrough material selection or material properties. In addition, acomposite of materials can be used to provide a region of reducedstiffness or rigidity. Moreover, a combination of any suitabletechniques can be used. Nevertheless, the illustrated region 172, whichis configured with reduced thickness, provides a simple manner ofachieving the region of reduced stiffness 172. In addition, by adjustingthe stiffness of the reduced stiffness region 172, the force required toinduce rolling of the region 172 can be controlled, which controls theforce applied against the nose of the user. For example, by varying thestiffness, movement can become increasingly or decreasingly resistedover the range of movement.

When the upper portion 154 comprises the region of reduced stiffness172, the upper portion 154 of the mask seal 110 tends to balloon outwardunder internal pressures, such as those encountered during positivepressure therapy regimens, which ballooning is believed to be caused bythe region of reduced stiffness 172 that defines a large area ofsilicone without significant structure. With reference to FIG. 4 andFIG. 12, to reduce the prevalence of ballooning in the upper portion 154and to provide enhanced structure in the upper portion 154, areinforcing component or components, such as a band 174, can bepositioned along at least a portion of the upper portion 154. The band174 can be a component formed of a material that is more rigid than, orthat features increased stiffness relative to, the silicone or othermaterial forming the mask seal 110. For example, a region ofsignificantly increased thickness relative to the region of reducedstiffness 172, where the region is formed of the same material formingthe mask seal 110, can be used to increase the stiffness of thereinforcing component or components.

In some configurations, the band 174 can be a separately formedcomponent that is at least partially encased by the material of the maskseal 110. In the illustrated configuration, the band 174 can be acomolded plastic component or the mask seal 110 can be overmolded ontothe band 174. In some configurations, the band 174 can be defined by aportion of the upper portion 154 that has enhanced stiffness relative tosurrounding regions. For example, but without limitation, the band 174can be defined by a portion of increased thickness, a portion ofdiffering materials or material properties that result in increasedstiffness or the like.

With reference to FIG. 9, the band 174 extends along at least a portionof the upper portion 154 of the mask seal 110. The upper portion 154 ofthe mask comprises an apex 180 when viewed from the front. The apex 180can be defined as a tip, a top and an angular summit of the mask seal110, which apex 180 is positioned in proximity to the nose of the userwhen in use. A first wall 182 and a second wall 184 converge at the apex180 in the illustrated configuration.

In some configurations, at least a portion of the first wall 182 and atleast a portion of the second wall 184 are reinforced by one or morecomponents or structures, such as the band 174. In the illustratedconfiguration, the reinforcing component or components, such as the band174 for example, reinforces at least a portion of the first wall 182 andat least a portion of the second wall 184. In some configurations, thereinforcing component or components, such as the band 174 for example,reinforces at least a portion of the first wall 182, at least a portionof the second wall 184 and the apex 180.

With continued reference to FIG. 9, the illustrated band 174 has a firstend 186 and a second end 188 that is opposite to the first end 186. Insome configurations, the band 174 can be formed separate of the maskseal clip 112 and attached to the mask seal clip 112 by one or moreflexible components. In some configurations, the band 174 can beconnected by a mechanical hinge structure to the mask seal clip 112. Inthe illustrated configuration, the first end 186 and the second end 188are positioned on the same side of the hinge axis H as the apex 180.Preferably, the first end 186 and the second end 188 are spaced awayfrom the hinge axis H toward the apex 180.

As shown in FIG. 12, the bend 152 and the stiffer region (e.g., regionof thicker cross section) adjacent to the region of reduced stiffness172 help to initiate rolling of the region of reduced stiffness 172. Inother words, a controlled buckling of the region of reduced stiffness172 occurs with the assistance of the adjacent stiffer portions. Inaddition, positioning an edge of the relatively more rigid mask sealclip 112 adjacent to the bend 152 further helps to induce rolling in thereduced stiffness region 172. In some configurations, the region ofreduced stiffness 172 is bounded by a first boundary and a secondboundary, wherein the first boundary and the second boundary have anincreased stiffness relative to the region of reduced stiffness. In theillustrated configuration, for example, the first boundary is defined byor alongside the band 174 while the second boundary is defined by oralongside the bend 152. In some configurations, the second boundary canbe defined by or alongside an edge of the more rigid mask seal clip 112.In some configurations, the second boundary can be defined along aportion of the mask seal 110 positioned between the mask seal clip 112and the region of reduced stiffness 172.

As the upper portion 154 of the mask seal 110 is displaced about thehinge axis H, the roll increases in size. In other words, as the firstboundary initially moves toward the second boundary, a roll is formed inthe mask seal 110. As the first boundary continues to move toward thesecond boundary, the roll continues to increase in size. Thus, in theillustrated configuration of FIG. 11, the roll defined in the upperportion 154 starts at nothing and progressively increases duringdisplacement of the upper portion 154 as shown in dashed lines.Preferably, the rolling between the first boundary and the secondboundary creates a single bend or inflection between the first boundaryand the second boundary. The single bend results in legs approaching thebend location that increase in size as the first boundary moves towardthe second boundary. In other words, the rolling created by movement ofthe first boundary toward the second boundary preferably does not resultin a fan-folding appearance such as a pleated configuration.

With reference again to FIG. 3, the mask seal 110 can have a geometrythat helps facilitate continued rolling of the region of reducedstiffness 172 following the initiation of the rolling. Arc lengths canbe defined in general from a first intersection of the hinge axis H withthe mask seal 110, up and over the upper portion 154 of the mask seal110, and back down to a second intersection of the hinge axis H with themask seal 110.

As shown in FIG. 3, the illustrated mask seal 110 comprises at least afirst arc length A (shown in dashed line), a second arc length B (shownin dash-dot chain line) and a third arc length C (shown along a base ofthe band 174). The first arc length A preferably is longer than the arclength of the mask seal clip 112 directly adjacent to the first mask arclength A. The second arc length B is positioned between the first arclength A and the third arc length C and the second arc length Bpreferably is shorter than the third arc length C and longer than thefirst arc length A. In some embodiments, the arc lengths steadilyincrease from the bend 152, or another region close to the outer surface170, proximal toward the band 174. In other words, as an angle α (seeFIG. 4) increases from the first arc length A, the arc length generallyincreases. In some configurations, the arc lengths can be substantiallyconstant from front to rear (i.e., as the angle α increases); however,by increasing the arc lengths away from the portion that initiates theroll, further movement of the apex 180 in a distal direction results incontinued rolling of the mask seal 110 over itself and over the outersurface 170, as shown in FIG. 11.

With reference again to FIG. 4, the upper portion 154 of the illustratedmask seal 110 also comprises a variable radius when viewed from the sideprofile. As shown, R1>R2>R3. Thus, in the illustrated mask seal 110, theradius decreases from proximal to distal as the angle increases. In someconfigurations, the radius need not decrease in this manner; however,the decreasing radius is believed to aid in rolling of the mask seal110.

Moreover, a radius r1 of the mask seal clip 112 from the hinge point Hpreferably is smaller than the radius R3 of the mask seal 110. Given thepliant nature of the mask seal 110, however, it is possible for theradius r1 and the radius R3 to be substantially the same while stillproviding for the mask seal 110 to roll over the mask seal clip 112. Inthe illustrated configuration, however, the difference between theradius r1 and the radius R3 results in an offset. The offset provides anability to slightly increase the side profile radius 136, as describedabove, without significantly impacting the ability of the mask seal 110to roll over the mask seal clip 112. If the offset were not provided,the ability to increase the side profile radius 136 would be verylimited.

As discussed above, the flange 160 encircles the generally tear-dropshaped opening 162. As is known, hoop stress can be defined ascircumferential stress in a cylindrically shaped part as a result ofinternal pressure. Thus, hoop stress increases as a ring attempts toexpand. It is believed that hoop stress resulting from seating arespiratory mask can be a source of some discomfort to the user,especially in the region of the bridge of the nose. The lower portion156 of the illustrated mask assembly 102 generally is secured inposition while the nasal or upper portion 154 moves relative to the noseof the user. Because of the rolling action described above, theillustrated full face mask assembly 102 acts to roll away from the nose,which decreases the incidence of increasing hoop stress, especiallyaround the bridge of nose. Thus, the rolling mask configuration providesa means for maintaining or reducing hoop stress during seating of themask.

As discussed above and as shown in FIG. 11, the upper portion 154 of theillustrated mask seal 110 rolls over the outer surface 170 in theillustrated configuration. The rolling over an external mask surfacemakes use of the positive pressure present within the full face maskassembly because the increased air pressure enhances the ability of themask seal to roll on itself (i.e., the air pressure decreases a surfacetension between the two surfaces of the mask seal that slide relative toeach other during rolling) and the slight ballooning effect helps toreduce the likelihood of buckling, creasing or undesired folding of themask seal 110. Furthermore, in some configurations, the external rollover can provide a visual cue of the degree or angle of displacement ofthe upper portion 154 of the mask seal 110 relative to the lower portion156 of the mask seal 110.

In order to provide an enhanced indication to the user of the extent towhich the upper portion 154 of the mask has rolled, it is possible toemploy a visual indicator. For example, in some configurations, a scalecan be imprinted, embossed or otherwise arranged on or near the reducedstiffness region 172. In some configurations, a scale can be positionedalong a portion of the mask 100 over which the reduced stiffness region172 will roll. For increased fidelity, the scale preferably ispositioned in a central location such that the extent to which thereduced stiffness region 172 rolls can be maximized. The scale can be anumerical scale or a color gradient scale, for example but withoutlimitation.

In some configurations, a ratchet or lock mechanism can be integratedwith the mask such that the reduced stiffness region 172 can be set at adesired roll point. For example, a ratchet mechanism with a series ofteeth that engage a closure member (e.g., ziptie locking ratchets) canbe used. When the upper portion 154 of the mask is displaced about thehinge point, the lock mechanism enables the upper portion 154 to beretained in position when the mask 100 is removed from the face of theuser U. Preferably, the lock mechanism allows that locked position to bereleased easily as desired such that, if the mask is moved too far, theupper portion can be relaxed into a better fitting position. Thus, theuser can set the extent to which the upper portion 154 rolls once andeach subsequent use would result in the same level of roll.

By rolling, the upper portion 154 (i.e., the portion of the seal memberthat contacts the bridge of the nose) moves as increasing pressure isapplied by the flange 160 of the mask against the face of the user. As aresult of the movement, the force exerted by the upper portion 154 uponthe bridge of the nose is substantially constant over a wide range ofpressures exerted by the lower portion 156 against the rest of the faceof the user. Similarly, the force required to cause the upper portion154 to move is substantially constant. As shown in FIG. 28, theillustrated configuration results in a full 25 mm change in position ofthe upper portion with an increase of less than about 0.5 N of forceassociated with that range of movement. Because the force applied to thenose is generally constant over a range of angles and associated upperportion displacement, the force applied to the bridge of the nose doesnot vary significantly at various headgear tension levels. Again, such aresult is shown in FIG. 28, wherein the total change in force over therange of 5 mm to 25 mm of movement at the apex 180 results in a forcechange of about 0.2 N. In addition, because the force applied to thenose is generally constant over a range of angles, the mask can beadjusted to improve fitting to a variety of facial geometries whilelimiting the pressure exerted against the sensitive bridge of the noseregion.

When compared to constructions featuring pleated geometries, the use ofa rolling configuration provides marked improvement. First, externalrolling rather than pleating reduced or eliminates the likelihood of thematerial of the mask seal encroaching into the chamber designed tocontain the nose of the user. Thus, external rolling reduces thelikelihood of contact with the nose of the user inside the chamberduring movement of the upper portion 154 relative to the lower portion156. Second, external rolling instead of pleating provides a cleanappearance and decreases the number of external cavities, which isbelieve to improve the user's perception of the full face mask assemblywhen compared to pleated assemblies.

With reference to FIG. 24, while the illustrated mask seal 110 rollsover the outer surface 170, the mask seal can be configured to rollinside the mask assembly. In other words, an internal roll over can beused in some configurations. The internal roll over is less desirablerelative to the external roll over because the positive pressure tendsto hinder rolling and because the rolling action tends to encroach intothe chamber that receives the nose. On the other hand, the internal rollover provides a cleaner appearance relative to the external roll overbecause any ballooning of the seal member is contained within the maskseal clip.

With reference now to FIGS. 1 and 2, the mask assembly 102 includes themask base 114, which is more rigid than the mask seal 110. The mask base114 can be formed of any suitable material. In some configurations, themask base 114 is formed of a polycarbonate material such that it iscapable of flexing for connection with the mask seal 110 and/or the maskseal clip 112.

With reference now to FIG. 14, the mask assembly 102 is shown with themask base 114 secured to the mask seal 110. More particularly, in theillustrated configuration, the mask base 114 is secured to the mask sealclip 112 that is attached to the mask seal 110 in any suitable manner.In some configurations, the mask base 114 and the mask seal 110 or maskseal clip 112 are removably connected. In some configurations, the maskbase 114 snaps together with one or both of the mask seal 110 and themask seal clip 112. Preferably, the mask seal 110 and the mask seal clip112 can be removed from the mask base 114 and a snap connection securesthe mask seal clip 112 to the mask base 114.

With reference to FIGS. 14 and 15, the illustrated mask base 114overlies at least a portion of the mask seal clip 112. In someconfigurations, the mask base 114 almost entirely covers the mask sealclip 112. In some configurations, the mask base 114 extends over morethan half of the mask seal clip 112. When the mask base 114 overlies asubstantial portion of the mask seal clip 112 or the mask seal 110, adouble layer effect is created (e.g., the mask seal clip 112 and themask base 114). The double layer effect provides increased insulationwhen a significant portion of the mask base 114 overlaps a significantportion of the mask seal clip 112 or the mask seal 110. The increasedinsulation provides a warmer inner portion (e.g., mask seal 110 and/ormask seal clip 112), which results in less rain out of humidity duringuse. Preferably, at least a portion of the mask seal clip 112 is exposedfrom under the mask base 114 such that the mask base 114 can be moreeasily separated from the mask seal clip 112. As shown in FIG. 15, toaid in the separation of the mask base 114 from the underlying mask seal110 and/or mask seal clip 112, the illustrated mask base 114 comprises aperipheral surface 200 on the proximal end. The mask base 114 is concaveon the inside to accommodate the underlying components. In other words,the mask base 114 is bowl shaped in a distal direction relative to theproximal peripheral surface 200.

The peripheral surface 200 comprises one or more recessed portions 202.Preferably, the recessed portions 202 comprise at least two recessedportions 202 that are positioned on opposite sides of the mask base 114from each other. The recessed portions 202 are configured to receive athumb and a finger such that the mask base 114 can be more easilyremoved from the front of the underlying mask seal clip 112. While therecessed portions 202 can define means for grasping the assemblyunderlying the mask base 114 for removal of the mask base, otherconfigurations can be used, such as outwardly extending tabs, protrudingportions and the like, for example but without limitation. In addition,while the illustrated recessed portions 202 are disposed on opposinglateral sides of the mask base 114, the recessed portions 202 can bepositioned on the top and bottom or on other regions as desired.

As shown in FIG. 13, the mask base 114 preferably comprises an opening210 that is defined by a wall 212. With reference to FIG. 14 (which is asection through the mask seal 110, the mask seal clip 112, and the maskbase 114), the wall 212 that defines the opening 210 through the maskbase 114 preferably fits within the wall 146 that defines the passage144 through the mask seal clip 112. As shown in FIG. 14, the wall 212can be axially coextensive with the wall 146. In addition, thedimensions and shapes of the walls 146, 212 can be such that the wallsinteract with each other to reduce relative slippage between the walls146, 212 and to reduce the likelihood of the mask seal base 114inadvertently separating from the mask seal clip 112. In someconfigurations, the walls 146, 212 fit together and reduce thelikelihood of leakage through the interface between the walls.Preferably, a taper lock secures the walls 146, 212 together.

With reference still to FIG. 14, the wall 212 comprises a contouredinner surface 214. The contoured surface 214 can be radiused to receivea ball end 220 of a swiveling elbow 222, such as that shown in FIG. 17.As better shown in FIG. 18, the ball end 220 has a contoured surface 224that can be snap fit into the contoured surface 214 formed in the maskbase 114. The connection between the two contoured surfaces 214, 224allows the surfaces to slide relatively freely with each other such thatthe position of the swiveling elbow 222 can be easily changed. In someconfigurations, the elbow 222 could be configured for rotation orswiveling without having a ball-joint configuration.

With reference again to FIG. 13, the mask base 114 also comprises atleast two pockets 230. The illustrated mask base 114 comprises twopockets 230. The pockets 230 recede into the mask base 114 and protruderearward from the mask base 114. The pockets 230 are received within therecesses 140 of the mask seal clip 112. Overlying the further recesses142 formed in the mask seal clip 112 are openings 232 that are definedby a surrounding wall 234.

The illustrated pockets 230 are formed such that one pocket 230 isformed on each lateral side of the mask base 114. The pockets 230 can bepositioned to be symmetrical relative to the central plane CP, whichplane substantially bisects the mask base 114. In some configurations,as shown in FIG. 15, the pockets 230 have an enlarged vertical dimension240 relative to a transverse dimension 242. Similarly, as shown in FIG.15, the openings 232 have an enlarged vertical dimension 244 relative toa transverse dimension 246.

In the illustrated mask base 114, the laterally inward portion of eachpocket 230 comprises a support wall 250. The support wall 250 ispositioned toward the center plane CP relative to normal to a basesurface 248 of the pocket 230. Each of the pockets 230 is configured toreceive a clip 252 (see FIG. 22). Once the clip 252 is installed withinthe pocket 230, the support wall 250 helps to limit rotation of the clip252 relative to the pocket 230. Moreover, the large vertical dimensionhelps users to locate the pocket 230 with the clip 252 duringinstallation.

With reference to FIG. 22, the clip 252 can have a two partconstruction: an outer cover 254 and an inner catch 256. Straps 260 canbe secured to each clip 252 in any suitable manner. One suitableconfiguration is illustrated in FIG. 2. In some configurations, thestraps 260 can be sandwiched between the outer cover 254 and the innercatch 256. In some configurations, loops or openings or holes could beprovided on the clips 252 through which the straps 260 are threaded.Preferably, one clip 252 can be connected to both an upper strap and alower strap of the headgear assembly 106. Such a configurationfacilitates easy connection of the headgear assembly 106 to the fullface mask assembly 102 and easy disconnection of the headgear assembly106 from the full face mask assembly 102.

As shown in FIG. 23, the clip 252 comprises a sloping surface 262. Thesloping surface 262 can be positioned on the outer cover 254. Thesloping surface 262 cooperates with the support wall 250 to help orientthe clip 252 relative to the pocket 203 of the mask base 114.

The clip 252 includes an interlock feature 264. The interlock feature264 is configured for insertion into the opening 232 defined in thepocket 230 of the mask base 114. The interlock feature 264 can engage ina snap-fit manner with a tab 236 defined along the wall 234 that definesthe opening 232 in the mask base 114, as shown in FIG. 13. Other mannersof interlocking the clip 252 with the pocket 230 also can be used.

Referring to FIG. 23, the interlock feature 264 of the illustrated clip252 comprises a U-shaped component 268 that terminates in a releaselever 266. The U-shaped end 268 protrudes a sufficient distance to allowthe connection with the tab 236 but does not protrude so far as to allowthe bottom of the further recess 142 in the mask seal clip 112 to stopproper insertion of the interlock feature 264 into the opening 232. TheU-shaped end 268 initially makes contact with a wall of the opening 232during connection of the clip 252 to the mask base 114. In theillustrated configuration, the U-shaped end 268 contacts the wall 234 ofthe opening 232 during insertion and the wall 234 guides the clip 252into position within the pocket 230. The opening 232, or one or moresurfaces that define the opening 232, generally align the clip 252relative to the mask base 114 during connection of the clip 252 to themask base 114.

The end of the release lever 266 protrudes through an opening 270defined by a wall 272. Preferably, the end of the release lever 266protrudes through the opening 270 a sufficient distance to allow easymanipulation of the release lever 266. Moving the release lever 266 inmanner that closes the U-shape of the interlock feature 264 allows theinterlock feature 264 to be removed from engagement with the tab 236 inthe wall 234 that defines the opening 232 in the mask base 112.

FIGS. 32-39 illustrate additional configurations of clip assemblies 252that are configured to secure a mask assembly 102 to a user's head. Theclip 252 of FIGS. 32 and 33, for example has a raised edge 400(sometimes referred to as a finger tab 400) that enables the user toeasily detach the headgear 106 from the mask assembly 102. The raisededges 400 are oriented such that the user may merely pull themrearwardly to pop the clips 252 off the mask base 114. Removing one ormore clips 252 from the mask base 114 allows the mask assembly 102 to beeasily removed from the user's head. The raised edge 400 provides agrasping point during attachment and removal of the headgear 106 withrespect to the mask assembly 102. For example, the user's thumb andindex finger may be placed on opposite sides of the raised edge 400during removal of the clip 252 from the mask assembly 102. In addition,the user may grip the clip 252 and maintain the grip throughout the maskfitting process. This eliminates the need to grasp blindly for straps260 during assembly. It also allows the user to attach the clip 252,remove it, and re-attach it while maintaining a grip on the raised edge400.

FIG. 34 shows an exploded view of the clip 252 of FIGS. 32 and 33. Theclip 252 includes an outer cover 254 and an inner catch 256. The innercatch 256 includes one or more slots 402 to receive the distal end ofthe headgear straps 260. The inner catch 256 can also include severalpressure bumps, such as those shown in connection with the configurationof FIGS. 38 and 39. The pressure bumps provide additional pressureagainst the outer cover 254 and inner catch 256, so that they aresecured to one another. In one configuration, the headgear straps 260are removable from the assembled clip 252.

The inner catch 256 includes an elongated slot 404, as shown in FIG. 38.The slot 404 includes a circular opening 406 having a diameter largerthan the width of the slot 404. The slot 404 and circular opening 406can include chamfered recesses to help align the clip 252 to the maskassembly 102. The circular opening 406 facilitates attachment andremoval of the clip 252 to the mask assembly 102, as will be discussedin greater detail below. Two channels 408 extend parallel to the sidesof the slot 404, thereby defining slot walls 410 (sometimes referred toas clip levers) on either side of the slot 404. The channels 408 aresized to permit adequate flexing of the slot walls 410 during attachmentand removal of the clip 252 from the mask assembly 102. In addition, theslot walls 410 extend along the longest dimension of the inner catch256, towards top and bottom, which allows longer slot walls 410 to beemployed. Longer slot walls 410 reduce the level of stress on the slotwalls when fitting the clip over the mounting post.

One configuration of a mask base 114 suitable for use with the clip 252of FIGS. 32-35 is illustrated in FIG. 36. The mask base 114 includes tworecesses 140 symmetrically positioned on opposite sides of the mask base114. A mounting post 412 extends from the body of the mask base 114within each recess 140. The mounting post 412 may be integrally formedwith the mask base 114, or separately formed and secured to the maskbase 114. The mounting post 412 can have a mushroom-shaped configurationto secure the clip 256 to the mask base 114 once the user snaps the clip256 in place. The rounded top of the bulbous mushrooms-shaped post 412helps locate and orient the central hole 406. As the clip 252 is pressedonto the post 412, the slot walls 410 deflect outwardly, away from thepost 412. Once the head of the post 412 clears the edge of the slot wall410, the slot walls 410 snap back to their original position, therebyproviding tactile and sometimes audible feedback that the clip 252 isproperly attached to the mask assembly 102.

The mounting post 412 can also comprise an elongated, elliptical,elevated portion 414 (sometimes referred to as a lug or wing) that issized to mate with the elongated slot 404 of the inner catch 256. Theelongated, elevated portion 414 comprises a chamfered edge to helpproperly align the head gear 106 with respect to the mask assembly 102.The portion 414 also prevents the clip 252 from rotating with respect tothe mask assembly 102. This helps assure constant tension on theheadgear straps 260 while the user sleeps.

FIG. 37 illustrates a partial assembly of yet another configuration tosecure a clip 252 to a mask base 114 of a mask assembly. The clip 252sits within a recess 140 of the mask base 114. A cylindrical,button-head post 412 extends from the surface of the mask base 114within the recess 140. The post 412 allows slight rotation of the clip252 when attached thereto due to its cylindrical configuration. However,as shown in FIGS. 38 and 39, the slot 404, channels 408 and slot walls410 extend along the shorter planar direction of the inner catch 256,towards its front and back ends.

The inner catch 256 also includes several pressure bumps 414. Asdiscussed above, the pressure bumps provide additional pressure againstthe outer cover 254 and inner catch 256, so that they are secured to oneanother.

Additional configurations of a clip 252 are illustrated in FIGS. 40-47.The clip 252 of FIG. 40 includes three elongated, elliptical slots 404and a finger tab 400. The finger tab 400 is used to create a lever torelease the clip 252 from a mask assembly 102. The central slot 404 issized to receive a mounting post 412 that extends from the outsidesurface of the mask body. One such suitable mounting post 412 isillustrated in FIG. 43. The mounting post 412 includes a ridge 414 andtwo slots 416. As the clip 252 is pressed onto the mounting post 412,the outer portions of the post 412 flex towards each other due to thespacing provided by the slots 416. Once the ridge 414 clears the uppersurface of the clip 252, the mounting post 412 snaps back to itsoriginal position, and the ridge 414 locks the clip 252 in place,

A similar configuration is shown in FIGS. 44-47. The clip 252 of FIG. 45does not include a finger tab and its central opening 404 has a rounder,more elliptical shape than the elongated slots of FIGS. 40-44.

All of the foregoing configurations simplify the procedure for securingthe mask assembly 102 to the user's head. For example, the clips 252allow the headgear 106 to open up so that it is not a closed loop. Byopening up, the headgear 106 may be swung around the head rather thanforcing the user to pull his head through it.

With reference to FIG. 2, in addition to the straps 260, the headgearassembly 106 also comprises a back strap 280 and a top strap 282. Otherhead gear assemblies also can be used. The back strap 280 extends aroundthe back of the head of the user U at a location generally above a napeof the neck but generally below the occipital protuberance. At alocation rearward of the ear of the user, the back strap 280 forks intoan upper arm 284 and a lower arm 286. The upper arm 284 arcs upward to alocation above the ear of the user and then arcs downward to a locationgenerally forward of the ear of the user. The lower arm 286 arcsdownward to a location generally below the ear of the user and extendsslightly forward of the ear.

The straps 260 can be connected to the back strap 280 in any suitablemanner. In the illustrated configuration, the straps 260 connect to theupper arm 284 and the lower arm 286 respectively. Preferably, the upperarm 284 and the lower arm 286 are more rigid than the straps 260 suchthat the arms 284, 286 generally maintain shape as the headgear assembly106 is being donned. In some configurations, each of the upper arm 284and the lower arm 286 supports its own weight. In some configurations,each of the upper arm 284 and the lower arm 286 is structured to betangle-free during donning. For example, the arms 284, 286 havesufficient torsion stiffness to reduce the likelihood of twisting whenbeing put on.

Preferably, the straps 260 connect to at least one of the upper arm 284and the lower arm 286 at a location forward of the ear. Such aconfiguration helps the user to locate the straps 260 without muchdifficulty. In addition, because the straps 260 in the illustratedconfiguration are embedded into the clips 252, the ends of the upperarms 284 and the lower arms 286 can comprise slots 290, 292 such thatthe straps 260 can be threaded through the slots 290, 292. In addition,the straps 260 can comprise an adjustment mechanism 294, such as aVelcro or buckle configuration. The adjustment mechanism 294 allows aforce between the mask seal 110 and the face of the user U to beadjusted. Any suitable adjustment mechanism 294 can be used.

As shown in FIG. 2, the top strap 282 preferably is flexible and has anadjustable length. The top strap 282 connects to the upper arms 284through a slot 296 and reduces the likelihood of the upper arms 284sliding down the head of the user and contacting the ears of the user.Preferably, the top strap 282 connects to the upper arms 284 at alocation generally above the ears of the user.

Advantageously, as shown in FIGS. 1 and 2, the straps 260 exert a forcein the direction of the arrow F while they connect to the mask base 114by movement in the direction C, which direction is generally normal tothe direction of the force F. In other words, the straps 360 aretensioned by pulling forward and the clips 252 are connected to the maskbase 114 by movement in a direction normal to the forward pull. Such aconfiguration eases securement of the interface 100 on the face of theuser.

In another configuration, the headgear assembly 106 includes asemi-rigid headgear 380 (as shown in FIG. 29) to secure the maskassembly 102 to the user's head. The semi-rigid headgear 380 is formedas a composite structure comprising a semi-rigid strap 382 that isjoined to a soft edging 384. For example, the soft edging 384 can bebonded to the semi-rigid strap 382 by plastic overmolding or by use ofan adhesive. As shown in FIG. 29, the soft edging 384 can be butt-joinedto the semi-rigid strap 382, without the soft edging 384 overlapping thesemi-rigid strap 382, to maintain the continuous profile of thesemi-rigid headgear 380. The semi-rigid strap 382 defines and maintainsthe semi-rigid headgear shape as tension is applied from the straps 260to pull the mask assembly 102 towards the user's head. In other words,the semi-rigid strap 382 is sufficiently rigid along its planar axis toprevent its upper and lower arms 284, 286 from overly deforming undertension. The semi-rigid strap 382 can be made from a variety of rigid orsemi-rigid materials, including plastic or metal. In someconfigurations, the semi-rigid strap 382 is made from PVC.

Especially in connection with a semi-rigid headgear assembly, it hasbeen found that the shape holding, or self-supporting nature, can resultin an overall assembly that is intuitive to fit. In particular, wherethe connection and/or headgear members are self-supporting such thatthey maintain a three-dimensional form, the headgear can be fitted inthe correct orientation with very little if any instruction. In aself-supporting arrangement, the tendency of the straps to not tanglealso reduces the time taken to fit the overall assembly.

As used herein, the term “semi-rigid” is used to denote that theheadgear assembly is sufficiently stiff such that the headgear assembly380 can assume a three-dimensional shape with dimensions approximatingthe head of the patient for which the headgear is designed to fit whilealso being sufficiently flexible to generally conform to the anatomy ofthe patient. For example, some of the other components (e.g., arms orstraps) of the headgear assembly 380 may also be partially or wholly“semi-rigid” such that the components are capable of holding athree-dimensional form that is substantially self-supporting. A“semi-rigid” headgear assembly is not intended to mean that each andevery component of the headgear assembly is necessarily semi-rigid. Forexample, the substantially three-dimensional form that theself-supporting headgear assembly 380 may assume may relate primarily tothe rear and top portions of the headgear assembly 380. In addition, thesemi-rigid headgear assembly 380 may include semi-rigid regions thatextend forward of the ears and above the ears when placed on the head ofthe patient.

The left and right upper and lower arms 284, 286 may be formed of asemi-rigid material, as well. Where used herein, the semi-rigidmaterials may include molded plastic or sheet materials that include butare not limited to homogeneous plastic materials and bonded non-wovenfiber materials.

In some configurations, one or more of arms or straps are formed of asubstantially inelastic material. The arms or straps can be formed of asemi-rigid, self-supporting material such that the semi-rigid headgearassembly 380 can assume a substantially three-dimensional shape andgenerally does not tangle. In some configurations, the material cancomprise a laminate structure of both conformable and semi-rigidportions, for example but without limitation. The semi-rigid strap 382may be of a self-supporting, resilient, substantially inelasticmaterial, such as Santoprene, polyolefin, polypropylene, polyethylene,foamed polyolefin, nylon or non-woven polymer material for example butwithout limitation. In some configurations, the semi-rigid strap 382 isformed from the polyethylene or polypropylene families. The material canbe a low density polyethylene such as Dowlex 2517, which is a linear lowdensity polyethylene that has a yield tensile strength of 9.65 MPa, abreak tensile strength of 8.96 MPa, and a flexural modulus—2% secant of234 MPa. The semi-rigid strap 382 preferably is formed of a materialsuch that the semi-rigid headgear 380 is substantially shape-sustainingunder its own weight regardless of its orientation. In someconfigurations, the semi-rigid strap 382 does not stretch more thanapproximately 6 mm under a 30 N tensile load. In some configurations,the semi-rigid strap 382 does not stretch more than approximately 3 mmunder a 30 N tensile load.

In some configurations, the semi-rigid strap 382 is formed from nonwoven polyolefin (NWP), which is bonded (e.g., overmolded or laminated)with a polyolefin. In such configurations, the overmolded polyolefinmaterial provides the principle shape sustaining properties. Inaddition, the softer NWP material is adapted to contact the skin andprovide a desired comfort level. Furthermore, the NWP material mayassist in providing the desired load bearing properties, such as thedesired tensile load bearing properties.

The semi-rigid headgear 380 is generally formed of a semi-rigidmaterial. Where used herein, the semi-rigid materials may include moldedplastic or sheet materials that include but are not limited tohomogeneous plastic materials and bonded non-woven fiber materials. Theupper and lower arms 284, 286 also include such semi-rigid materials, asthe arms 284, 286 are formed integrally with and are portions of thesemi-rigid headgear 380. Preferably, the right and left lower arms 286are formed as an integrated component that, in use, will extend aroundthe back of the head and above the neck of the patient.

A soft edging 384 covers or attaches to at least a portion of theperiphery of the semi-rigid strap 382. In one configuration, the softedging 384 does not cover the front or rear faces of the semi-rigidstrap 382. For example, the thicknesses of the soft edging 384 andsemi-rigid strap 382 can be the same at the location where they arejoined together.

The soft edging 384 provides a soft, comfortable interface between theperiphery of the semi-rigid strap 382 and the user's skin. The softedging 384 can be made from a variety of soft materials, including butnot limited to a plastic, an elastomer, silicone or thermoplasticpolyurethane (TPU) plastic. The soft edging 384 can have a Shorehardness in the range of 10-80 Shore A.

As used herein with respect to headgear and straps, “soft” is used todescribe a hand of the material, which means the quality of the materialassessed by the reaction obtained from the sense touch. In addition, asused herein with respect to headgear and straps, “conformable” is usedto describe the ability of the material to conform to the anatomicalfeatures of the patient (e.g., around a facial feature). In particular,a strap including at least an element of “soft” and/or “conformable”material also may be “semi-rigid” and/or axially inelastic.

The soft edging 384 can have a uniform thickness, or in someconfigurations, an uneven thickness. For example, in some configurationsthe soft edging 384 is the same thickness as the semi-rigid strap 382.In other configurations, the soft edging 384 is thinner than thesemi-rigid strap 382, forms a bulbous end to the semi-rigid strap 382,or is simply thicker than the semi-rigid strap 382. A variety ofcross-sectional views of the semi-rigid headgear 380 are shown in FIG.29. Each cross-sectional view (A-A′ through F-F′) shows one possibleconfiguration of semi-rigid strap 382 and soft edging 384 thicknesses,which may be combined as desired. For example, any one particular softedging 384 thickness and shape could apply to a portion or the entiresemi-rigid strap 382, or may be combined with any other particularcovering thickness and shape shown in FIG. 29.

Many other thickness configurations may be provided, as well. Inaddition, material thickness may be symmetrically or asymmetricallyapplied to the semi-rigid strap 382. For example, cross-sectional viewsC-C′ and F-F′ are shown as asymmetric; however, in other configurationsthe thickness of either end the soft edging 384 is symmetrically appliedto the semi-rigid strap 382. In some configurations the semi-rigid strap382 is selectively thickened to provide extra rigidity and support. Forexample, the second of the two configurations illustrated ascross-sectional view F-F′ has such a thickening. Finally, in someconfigurations, venting through-holes 396 are provided throughout thesemi-rigid headgear 380 (such as on the semi-rigid strap 382, as shownin FIG. 29, or on soft edging 384) to provide ventilation and sweatmanagement.

When laid flat, as shown in FIG. 29, the semi-rigid headgear 380 definesthree C-shaped, arcuate regions 386, 388, 390. Two ear-surroundingregions 386, 388 are defined by upper and lower arms 284, 286, and arear region 390 is defined by lower arms 286 and the back strap portion280. The semi-rigid headgear 380 is flexible enough to bend to adapt tothe shape of the user's head, such that the ear-surrounding regions 386,388 at least partially surround or encircle the user's ears, and therear region 390 at least partially surrounds or encircles the back ofthe user's head, above the neck.

The curvature of each arm 280, 284, 286 can be selected to provide acomfortable fit and to facilitate application and removal of thesemi-rigid headgear 380 from the user's head. For example, in theillustrated configuration, the upper arms 284 have a concave curvatureand the lower arms 286 have a convex curvature with respect to theopening in the upper ear surrounding arcuate regions 386, 388. The backstrap portion 280 and the lower arms 286 all have a concave curvaturewith respect to opening in the neck surrounding arcuate region 390.These curvatures facilitate application and removal of the semi-rigidheadgear 380 from the user's head by, for example, providing openings tothe arcuate regions sized and oriented to easily fit over a user's neckand ears.

The configuration of FIG. 29 utilizes integrated crown straps comprisingfirst and second crown arms 392, 394 to secure the semi-rigid headgear380 to the user's head. Once the semi-rigid headgear 380 is positionedto partially surround the user's head, the first and second crown arms392, 394 are brought into contact with one another to secure thesemi-rigid headgear 380 in place. Any of a variety of mechanisms can beprovided with the first and second crown arms 392, 394 to enable them toattach to one another. For example, in some configurations, ahook-and-loop fabric (e.g., Velcro), or one or more snaps or clips canbe used to attach the first and second crown arms 392, 394 to oneanother.

The crown straps extend laterally over the top of the skull in line withthe ears. When the crown straps extend in this manner and the arcuateregions 386, 388 are positioned to partially encircle the user's ears,the back strap 280 of the semi-rigid headgear 380 should locate on orbelow the inion. The user's inion is the most prominent projection ofthe occipital bone at the posterioinferior portion of the skull. Inother words, the inion is the highest point of the external occipitalprotuberance. The semi-rigid headgear 380 can be positioned on theuser's head according to any of the configurations described in theattached Appendix, which forms an integral part of the presentdisclosure and is bodily incorporated, herein.

For example, the back strap portion 280 is adapted to engage with therear of head of the user. Preferably, the back strap portion 280 isadapted to engage with the head at a location on or below the externaloccipital protuberance. The back strap portion 280 spans the distancearound the back of the head and extends to each side of the head. Insome configurations, the back strap portion 280 comprises a longitudinalcenter that is adapted to be located about 25 degrees below a horizontalplane that extends through the ear canal of the patient.

On either side of the head, the semi-rigid headgear 380 extends upwardand downward into left and right side regions that form arcuate regions386, 388. The side regions are adapted to extend behind the ears of thepatient. Preferably, the side regions also are adapted to extend behindthe mastoid processes of the patient. Each of the left and right sideregions of the semi-rigid headgear 380 extends into or comprises anarched portion 386, 388. The arched portions 386, 388 bend forward. Thearched portions 386, 388 are adapted to extend around the respectiveears of the patient. Preferably, each of the arched portions 386, 388terminates at a respective termination portion. The termination portionspreferably are adapted to be located forward of the ears of the patient.In some configurations, the side regions and the arched portions 386,388 of the semi-rigid headgear 380 do not include a soft inner paddingportion but may comprise a self-supporting, resilient material that isin direct contact with the head/hair of the patient.

The top portion of the semi-rigid headgear 380 connects the archedportions 386, 388 together. The top portion can be positioned forward ofthe ears in some configurations. Preferably, the top portion ispositioned generally vertical from the ears. More preferably, alongitudinal center of the top portion is adapted to be spaced more than13 mm, preferably between 13-100 mm, rearward of a vertical plane thatintersects the ear canals. In some configurations, the top portioncomprises a first segment 392 and a second segment 394 with the firstsegment 392 and the second segment 394 combining to form the topportion. The first segment 394 extends upward from an apex of the leftarched portion 386 while the second segment 392 extends upward from anapex of the right arched portion 388. Preferably, the top portion isformed of a self-supporting and semi-rigid material. In someconfigurations, the top portion does not include any backing, includinga soft padded backing layer.

Each of the upper and lower arms 284, 286 comprises a slot 292, 290 neareach arm end. Each slot is configured to receive straps 260 from themask assembly 102, as shown in FIG. 2. In addition, the portion 398 ofthe semi-rigid headgear 380 covered by straps 260 is thinner than thecorresponding arm 284, 286 in order to accommodate the thickness of thestrap 260. For example, as shown in FIGS. 30 and 31, the semi-rigidheadgear portion 398 is thinner than the arm 286. The portion 398 isdimensioned such that when the strap 260 is inserted into the slot 290and tensioned, its thickness will not extend beyond the arm 286. Bymaintaining the thickness of the strap 260 and the portion 398 less thanthe thickness of the arm 286, the strap 260 does not irritate the userwhen worn.

In addition, the upper arms 284 are configured to extend downward from alocation above the user's ear such that the adjustable top straps 260extend no closer than about 10 mm to the user's eye when worn. The lowerarm 286 is configured to be located off of the user's neck when the headis tilted up and down, and the termination point of the lower arm 286 islocated generally below the user's ears so that the lower strap asattached to the lower arm 286 angles upwards from the termination point290 to the mask assembly 120. In such a configuration, as illustrated inFIGS. 52 and 53, the lower straps and the upper straps form a triangle,and the space between the lower straps and the upper straps on the maskis smaller than the space between the lower straps and the upper strapson the headgear, thereby stabilizing the mask assembly 120 againstupward and downward movements.

With reference again to FIG. 17, the elbow 222 connects to a conduit 300through a disconnectable swivel assembly 302. As shown in the sectionview of FIG. 20, the elbow 222 comprises a stem 304 that comprises aninner wall 306 at the base. The inner wall 306 comprises a recess 308.

A sleeve 310 comprises a flange 312 that is received within the recess308. The sleeve 310 can be secured into position within the elbow 222using any suitable technique. The sleeve 310 comprises a generallycylindrical outer wall 314. The flange 312 comprises a section thatextends outward to connect to a lever 316. Preferably, the flange 312and the lever 316 are integrally formed. With reference to FIG. 21, thelever 316 includes a lower inwardly extending catch 320 and is capableof pivoting about the section that connects the lever 316 to the flange312. Thus, pressing inward on an upper portion 322 of the lever 316results in the catch 320 moving away from the generally cylindricalouter wall 314 of the sleeve 310.

A swivel 330 comprises a generally cylindrical inner wall 332. The innerwall 332 slides over the outer wall 314 of the sleeve 310 such that asliding fit results between the swivel 330 and the sleeve 310. An upperportion 334 comprises a shoulder 336. The catch 320 of the lever 316 cansecure the swivel 330 in axial position on the sleeve 310 by engagingwith the shoulder 336. When the upper portion 322 of the lever 316 isdepressed, the catch 320 moves away from the shoulder 336, which allowsthe swivel 330 to be removed from the sleeve 310.

A flap 350 can be mounted between the stem 304 and the sleeve 310. Inthe illustrated configuration, the flap 350 extends into a flow channel352 from a base 354 that is sandwiched between the stem 304 and thesleeve 310. The flap 350 can pivot upward (as shown in FIG. 20, seearrow P) about an axis X (see FIG. 21) away from the sleeve 310 suchthat flow from a positive pressure generator can continue generallyunobstructed to the user through the interface 100. The flap 350 pivotsdownward into contact with the sleeve 310 to seal the flow channel 352in the event that the positive pressure source stops providing apressurized flow of air. In some configurations, the flap 350 will notfully contact the sleeve 310. In some configurations, the flap 350 willnot seal the channel 352 when in the down position.

With reference to FIG. 21, a port 360 is defined through the elbow 222at a location above the flap 350. The port 360 preferably is positionedalong a portion of the elbow 222 that is in the vicinity of the axis X.In some configurations, the port 360 is positioned to be substantiallyshielded by the flap 350 from an inspiratory flow of air. In otherwords, as the air pivots the flap 350 away from the sleeve 310, the flap350 is moved into a position that at least partially or completelycovers the port 360.

In some configurations, the port 360 extends through a wall of the elbow222 that comprises a generally planar inner wall 362. The generallyplanar inner wall 362 helps the flap 350 to generally seal the port 360when the flap is moved upward away from the flange 312 of the sleeve310.

In some configurations, the lever 316 overlies a majority of the port360 such that the port 360 is generally obscured from view. As shown inFIG. 20, however, a gap 364 preferably surrounds at least a portion ofthe lever 316 such that a relatively free flow of air can pass throughthe port 360 when the flap 350 does not overly the port 360. Inaddition, in some configurations, the port 360 and the lever 316 arepositioned on a same side of the elbow 222 as an opening 370 definedwithin the ball end 220, which opening is positioned within the maskassembly 102 when the connection port assembly 104 is assembled to themask assembly 102. Advantageously, such a positioning places the port360 in a position on the elbow 222 that faces the user. Such a locationfurther obscures the port 360 from view during use, which results in amore aesthetically pleasing configuration. Moreover, because flowthrough the port 360 will be very infrequent, having the port 360disposed toward the user will not cause any significant discomfort forthe user.

While not shown, the elbow 222 also can comprise one or more bias flowvent holes. The bias flow vent holes preferably are positioned in aforwardly directed orientation such that any bias flow does not directlyimpinge upon the user.

Another configuration of an elbow assembly 302 is illustrated in FIGS.48-51. The elbow assembly 302 comprises an elbow 222, a sleeve, 310,and/or a swivel 330, as shown in FIG. 49. In some configurations, theelbow assembly 302 only includes the elbow 222 and sleeve and omits theswivel 330. The swivel may be permanently or removably attached to thesleeve 310 and elbow 222; in some configuration, the swivel 330 isintegrally formed with the end of the delivery conduit. A flap 350 ispositioned over the sleeve 310 such that it at least partially obstructsthe sleeve's flow channel 352. The elbow assembly 302 functionssimilarly to the elbow assembly 302 of FIGS. 17-21; however, the elbowassembly 302 of FIGS. 48-51 provides the additional benefit of directinggases away from the patient when the flap 350 drops to its closedposition (as shown in FIGS. 50 and 51).

With reference to FIG. 49, the sleeve 310 preferably comprises two ormore cut out regions or recesses 356. The recesses 356 can have anysuitable shape and, in the illustrated configuration, the recesses 356comprise a semicircular configuration that extends upward into thesleeve 310. The sleeve 310 also comprises at least one bump 357, andpreferably two or more bumps 357. Preferably, each of the bumps 357extends around an arc of about 70 degrees. More preferably, each of thebumps 357 is generally centered between two recesses 356 and each of thebumps 357 extends about 70 degrees around an outer surface of the sleeve310.

The swivel 330 preferably is generally cylindrical in configuration. Asshown in FIG. 49, the swivel 330 has an inwardly extending ridge 358.The ridge 358 preferably encircles the entire inner surface. In someconfigurations, the ridge 358 can be interrupted. Preferably, however,the ridge 358 does not have any interruptions large enough toaccommodate the entire bump 357 such that the ridge 358 and the bump 357can cooperate to keep the swivel 330 mounted over the sleeve 310. Whenassembling the swivel 330 to the sleeve 310, the recesses 216 allow thebumps 220 to deflect inward such that the bumps 357 can slide over theridge 358 and then snap back outward to secure the bumps 357 under theridge 358.

The elbow 222 comprises openings 420 at its sides that are in fluidcommunication with an air venting channel 422. The air venting channel422 is formed by the spacing between the elbow's inner and outer walls362, 424, as shown in FIGS. 50 and 51.

When the flap 350 drops to its closed position, as shown in FIGS. 50 and51, air exhaled from the user enters opening 370 of the elbow 222. Theexhalation flows through the port 360 in the elbow's inner wall 362, andthrough the venting channel 422 until it exits the elbow 222 via theopening 420.

The configuration of FIGS. 48-51 provides a reduced overall length andimproves product aesthetic by eliminating an unsightly hole positionedat the front of the elbow 222. In addition, the configuration of FIGS.48-51 and improves patient comfort by preventing air from being directedtowards the user. Instead, openings 420 direct air flow out of the sidesof the elbow 222 and away from the patient.

With reference to FIG. 54, a flexible headgear assembly 500 can be usedto secure a mask assembly to a user's head for respiratory therapy, forexample but without limitation. The illustrated flexible headgearassembly 500 can be used with any suitable mask assembly, including butnot limited to any of the mask configurations disclosed herein.

The illustrated flexible headgear assembly 500 comprises a back strapportion 502. At least a portion of the back strap portion 502 is joinedwith a panel 504. In the illustrated configuration, the back strapportion 502 is configured to span a distance around the back of theuser's head and is configured to extend toward each lateral side of theuser's head.

With continued reference to FIG. 54, a pair of upper arms 506 and a pairof middle arms 510 can extend generally transversely from a top edge 512of the back strap portion 502. A pair of lower arms 514 can extendgenerally transversely from a lower edge 516 of the back strap portion502. In some configurations, the pair of lower arms 514 extend down andaway from the back strap portion 502 such that a lower edge of the lowerarms 514 will be positioned lower than the bottom edge of the back strapportion 502. In some configurations, the pair of middle arms extendupward and away from the back strap portion 502 such that the middlearms 510 have an upper edge that is positioned higher than the upperedge of the back strap portion.

The lower arms 514 and the middle arms 510 terminate with ends 520 inthe illustrated configuration. The ends 520 can comprise securingportions 522, which can be formed of hook or loop components for ahook-and-loop style fastening arrangement. Preferably, and as will bedescribed in more detail below, the securing portions 522 comprise atleast hook portions that can engage with the material of another portionof the headgear assembly 500. Each of the upper arms 506 also canterminate with regions comprising a securing portion 524.

When positioned on the head of a user, the back strap portion 502 islocated on or below the external occipital protuberance and above thenape of the neck of the user. The upper straps 506 can be connectedtogether in any suitable manner. In some configurations, a clip securesthe upper straps 506 together with the securing portion 524 doubled backand secured to another portion of the upper straps 506. Thus, the upperstraps 506 can extend generally over a top of the head of the user tolimit downward movement of the balance of the headgear assembly 500.

The middle arms 510 and the lower arms 514 can be connected to a clip(not shown) or another portion of the mask assembly such that the middlearms 510 and the lower arms 514 secure the headgear assembly 500 to themask either directly or indirectly (e.g., with a clip, such as thatshown in FIG. 40, for example but without limitation). The ends 520 ofthe middle arms 510 and the lower arms 514 can be passed through loopsor other structures on the mask assembly and doubled back with a fold.The overlapping portions can be secured in any suitable manner. Forexample but without limitation, the overlapping portions can be securedwith a hook-and-loop fastening arrangement (e.g., Velcro® fasteners).

With reference now to FIG. 55, at least one of the end portions of theupper arms 506, the middle arms 510 and the lower arms 514 can compriseenlarged ends 520. Preferably, the enlarged ends 520 are formed on atleast the middle arms 510 and the lower arms 514 of the flexibleheadgear 500. In some configurations, the enlarged ends 520 can be foundon one or more arm that connects to the mask assembly. The enlarged ends520 can be integrally formed with the main portion of the arms 510, 514.

As described above, the arm 526 can be formed integrally with theenlarged end 520. The illustrated enlarged end 520 has a width d whilethe arm 526 has a width e. The width e of the arm 526 can be betweenabout 12 mm and about 20 mm, between about 14 mm and about 18 mm, orpreferably about 16 mm. The width d of the enlarged end 520 can bebetween about 18 mm and about 26 mm, between about 20 mm and about 24mm, or preferably about 22 mm. In some embodiments, the differencebetween the largest width d of the enlarged end 520 and the arm width eis between about 3 mm and about 10 mm, or between about 5 mm and about 8mm. In some configurations, the difference between the largest width dof the enlarged end 520 and the arm width e is about 6 mm. Because thewidth d of the enlarged end 520 is greater than the width e of the arm526, an edge of the enlarged end 520 can more easily be located suchthat the portion used to secure the end 520 to the arm can be moreeasily located in order to refit the arm 526 (e.g., in order to tighten,loosen, remove, or otherwise reposition the flexible headgear 500).

Moreover, when the width d of the enlarged end 520 is greater than thewidth e of the arm 526, a neck portion 536 can be formed at a locationbetween the enlarged end 520 and the arm 526. The neck portion 536 canprovide reduce the likelihood of the enlarged end 520 sliding out of theattachment portion on the mask assembly when secured to the user's head.For example, an opening in the attachment portion on the mask assemblymay be about 16 mm to about 18 mm wide while the enlarged end 520 may beabout 22 mm and the arm 526 may be about 16 mm. Accordingly, thelikelihood of the enlarged end 520 inadvertently pulling through theopening is greatly reduced.

The geometry of the neck portion 536 can further reduce the likelihoodof the enlarged end 520 inadvertently pulling through the opening. Anysuitable transition can be used. As illustrated in FIG. 56, the neckportion 536 can be curved to facilitate removal of the arm from the maskassembly, when desired. The neck portion can extend at an angle betweenabout 0 degrees and about 90 degrees relative to the arm. Preferably,the neck portion 536 extends at an angle of between about 20 degrees andabout 60 degrees. In some configurations, the neck portion 536 can be amore abrupt transition or a less abrupt transition. The more abrupt thetransition, the less likely the arm will inadvertently separate from themask assembly.

The neck portion 536 forms a portion of the geometry of the enlarged end520. In some configurations, the enlarged end 520 can be substantiallyoval-shaped. In some configurations, the enlarged end 520 can beconfigured to resemble various shapes, including, for example, aparallelogram, an ellipse, a circle, a triangle, or any other suitableshape.

With continued reference to FIG. 55, each of the enlarged ends 520 cancomprise an embedded panel 522 having hook fasteners or the like. Thepanels 522 can be located on the enlarged ends 520 such that theenlarged ends 520 can be secured to another portion of the correspondingarm when the arm has been folded back over itself. The embedded panels522 can be comprised of a hook-fabric (e.g., Velcro®). Thus, theenlarged ends 520, and the hook materials of the panels 522 inparticular, can be fastened onto another portion of the correspondingarm to secure the headgear assembly 500 to the mask assembly.

The panels 522 can be attached to the ends of the arms in any suitablemanner. In some configurations, the panel 522 is attached to theenlarged end 520 by ultrasonic welding. For example, the panel 522 canbe located in a desired location along the arm and then the ultrasonicwelding process can effectively melt the two materials together. Withreference to FIG. 56, when ultrasonic welding is used to attach theenlarged hook-fabric panel 522 to the enlarged end 520, a weld edge 530having width a is formed around a perimeter of the enlarged hook-fabricpanel 522. As a result of the ultrasonic welding procedures in theillustrated configuration, a width a of the weld edge 530 isapproximately 3 mm. An area of the hook-fabric panel 522 that comprisesthe weld edge 530 generally is not functional to engage hook-receptivematerials as a result of the ultrasonic welding procedure melting orotherwise deforming the hooks of the hook-fabric. Thus, a functionalsurface area of the hook-fabric panel 522 is decreased by a surface areaequal to that of the weld edge.

The weld edge 530 can be bound by a soft edge 532 having width bcomprised of the hook-receptive breathable composite materials of theenlarged end 520. Preferably, the weld edge 530 is recessed below thesurface of the soft edge 532. A projection of the width e of the arm 526can extend through the weld edge 530 such that the soft edge 532 wouldbe positioned slightly outward of the projection of the width e of thearm 526.

The width b of the soft edge can be from about 0.5 mm to about 4 mm,from about 1 mm to about 3 mm, or preferably about 2 mm. An active hookportion 534 can adjoin the weld edge 530 and have a width c. The width cof the active hook portion can be slightly narrower than the width e ofthe arm 526. By increasing the width c, the functional surface area ofhook-fabric material can be increased, thus improving a sheer forceresistance and durability. By having the width c smaller than the widthe of the arm 526, the arm 526 reduces the likelihood of the active hookportion 534 contacting the skin of the user. The width c of the activehook-fabric portion 534 can be from about 8 mm to 16 mm, from about 10mm to about 14 mm, or preferably about 12 mm. The enlarged end width eenables the width c of the functional surface area to be increased. Inother words, the end of the arm has been enlarged such that the width ofthe active hook portion 534 can be increased, which can provide a moresecure attachment of the enlarged end to the surface of the arm.

The flexible headgear assembly 500 can be formed of any suitablematerial. In some configurations, the flexible headgear assembly 500 canbe covered with or have at least some portion formed of a hook-fastenerreceptive breathable composite material. In some configurations, theflexible headgear assembly 500 can be at least partially formed ofNylon/Lycra Breath-O-Prene® material. In some embodiments, when a 150 mmlong by 20 mm wide sample of the material is subjected to a 10 N axialload, the sample elongates to about 207 mm, which is an elongation ofabout 38% caused by the 10 N axial load. Thus, the material preferablyis fairly elastic. In some embodiments, the headgear assembly 500 cancomprise one or more rounded edges. The rounded edges can be formed inany suitable manner. In some configurations, the rounded edges areformed by applying heat and pressure to the edges of the headgearassembly 500. In some configurations, the rounded edges are formed in amanner similar to the techniques described in U.S. Pat. No. 3,295,529,which is hereby incorporated by reference in its entirety.

As introduced above, the back strap portion 502 of the illustratedflexible headgear assembly 500 preferably comprises at least onerelatively inelastic panel 504. The panel can be formed of a relativelylow-stretch material, such as a polyester Breath-O-Prene® material, forexample but without limitation. In some embodiments, when a 150 mm longby 20 mm wide sample of the material is subjected to a 10 N axial load,the sample elongates to about 160 mm, which is an elongation of about 7%caused by the 10 N axial load. Thus, the material preferably is fairlyinelastic or non-stretch when compared to the more elastic material ofthe flexible portion.

Because the panel 504 is formed of a less elastic material than thesurrounding portions of the headgear assembly 500, the panel 504 resistsstretching in at least a portion of the headgear assembly 500. Byresisting elongation of at least a portion of the otherwise elasticheadgear assembly, the panel helps maintain the headgear 500 in adesired shape and helps maintain the headgear 500 at a desired locationrelative to a back of the user's head.

Testing has shown that, without the use of the panel 504, elongation inthe back of headgear assembly 500 can cause the headgear assembly toelongate and move downward toward the user's neck when increasing loadsare applied to the lower straps. FIGS. 57A and 57B illustrate the effectof applying increasing force to the lower arms 514 of the flexibleheadgear 540 with a back strap portion 544 completely comprised of anelastic material. The illustrated configuration in FIGS. 57A and 57B donot feature the panel 504.

As described above, the back strap portion 544 is positioned in adesired location when it is located on or below the external occipitalprotuberance and above the nape of the neck of the user. In FIG. 57A,the back strap portion 544 is shown in a more preferred position. To aidin visualizing movement, position markers 546 are shown on the testingmodel 542. When increasing loads are applied to the lower arms 514, asshown in FIG. 57B, the elastic nature of the back strap portion 544allows it to elongate and deform, which allows the back strap portion544 to move downward along the neck of the user. Reference to theposition markers 524 illustrates the movement. With downward movement,more force from the back strap portion 544 is applied to the neck ratherthan the head, which is less desired. Because the flexible headgear 540can be worn for a period of minutes to hours, or for a period of hoursto days when used for respiratory therapy, the lowered positioning ofthe back strap portion 544 can create discomfort for the user.

In order to reduce the degree of elongation of the back strap portion502 when increasing force is applied to the lower arms 514, theless-elastic panel 504 can be attached to the back strap portion 502. Insome configurations, the panel 504 can comprise of a substantiallynon-stretch insert 560. The insert 560 can be attached to the back strapportion 502, for example, by over-lock stitching, by ultrasonic welding,by use of glue or other adhesives, or by any other method known to thoseof skill in the art. When the insert 560 is attached to the back strapportion 502, it can provide a greater tension resistance, which allows agreater force to be applied to the lower arms 514 when attaching andusing the flexible headgear 500. Thus, the insert 560 can advantageouslyreduce deformation of the back strap portion 502 and aid in keeping itlocated in a desired position relative to the head and neck of the user.

As illustrated in FIGS. 58A-58D, the non-stretch insert 560, 562, 564,566 can be configured in a variety of shapes, including but not limitedto those shown in FIGS. 58A-58D. Preferably, the non-stretch insert 560,562, 564, 566 adjoins or covers at least the backstrap portion 502. Insome configurations, the non-stretch insert 562, 564 adjoins or coversat least a portion of the lower arms 514. In some configurations, thenon-stretch insert 562, 564 adjoins or covers at least a portion of ajunction between the lower arms 514 and the backstrap portion 502. Insome configurations, the non-stretch insert 564 adjoins or covers atleast a portion of the middle arms 510. In some configurations, thenon-stretch insert 564 adjoins or covers at least a portion of ajunction between the middle arms 510 and the backstrap portion 502. Insome configurations, a height of the non-stretch insert 560 is at leastabout half of a height h of the back strap portion 502. In someconfigurations, the height of the non-stretch insert 560 is preferablymore than about half of the height h of the back strap portion 502. Byleaving a portion of the back strap portion 502 formed of the moreelastic material, the back strap portion 502 is able to stretch andconform in a limited degree but more than would be possible with a backstrap portion fully formed from a less elastic material.

The non-stretch insert 560 can be configured to have any suitablesurface area. The non-stretch insert 560 can be configured to extendalong varying lengths of the lower edge 516 of the back strap portion502. In some configurations, the non-stretch insert 560 extends alongmore than half of the lower edge 516 of the back strap portion 502.Preferably, the non-stretch insert 560 extends along substantially allof the lower edge 516 of the back strop portion 502. Otherconfigurations are possible.

With reference now to FIG. 59, an assembly is illustrated comprisingheadgear 600 having two or more straps that can be connected with awinged buckle 602. As with the other headgear described herein, theheadgear 600 can be used with any suitable mask assembly, including butnot limited to any of the mask configurations disclosed herein.Moreover, the illustrated configuration comprises straps that areconnected by a winged buckle 602 and such a configuration can be usedwith any of the headgear disclosed herein, for example but withoutlimitation.

In the illustrated configuration of FIG. 59, the headgear assembly 600comprises at least a pair of upper arms 606. Each of the upper arms 606can terminate with ends 608. In some configurations, at least one of thepair of upper arms 606 comprises a securing portion, such as any of thesecuring portions described elsewhere. In the illustrated configuration,each of the upper arms 606 comprises a securing portion. Preferably, thesecuring portions are positioned at least partially on the ends 608. Insome configurations, the securing portions can be formed of hook or loopcomponents for a hook-and-loop style fastening arrangement. Preferably,the securing portions comprise at least hook portions that can engagewith the material of another portion of the headgear assembly 600.

With reference to FIG. 59, the upper arms 606 can be joined by thewinged buckle 602, for example but without limitation. As illustrated inFIG. 61, the winged buckle 602 can comprise a body 610 that defines atleast one slot 612, and preferably at least two slots 612. The at leastone slot 612 accommodates the ends 608 of the straps 606 such that theends 608 of the straps 606 can be passed through the at least one slot612 and then folded over and secured in position with the securingportions as described above.

The body 610 of the illustrated buckle 602 comprises a tri-glide slideconnector portion 614 and a pair of wings 616. Accordingly, the at leastone slot 612 can be defined by the tri-glide slide connector portion614. In some configurations, however, the at least one slot 612 can beformed by one or more of the following (including multiples of one ormore of the following components): a loop, a square ring, a D-ring, anoval ring, a sliplock buckle, a ladder lock or the like.

The wings 616 advantageously provide support to the straps 606 suchthat, as shown in FIG. 59, the headgear assembly 600, including thestraps 606 can substantially maintain a three dimensional shape. In someconfigurations, a buckle without wings will allow folding and floppingof the headgear assembly and more particularly the straps 606 about thebuckle, which can cause the headgear assembly to not substantiallymaintain a three dimensional shape. Accordingly, the wings 616 have beenfound to enhance usability of the headgear assembly 600.

With reference to FIG. 62, laterally outward extents 618 of the wings616 extend downward beyond a lower surface 620 of the connector portion614. By extending the lateral extents 618 below the lower surface 620,the buckle 602 can better conform to and/or follow a crown of a head ofa user relative to a flat buckle. In some configurations, however, thelaterally outward extents 618 may not extend downward below the lowersurface 620 and/or the bottom of the buckle, including the wings, may besubstantially flat or rounded.

The buckle 602 can be formed of any suitable material. In someconfigurations, the buckle 602 can comprise two or more differentmaterials such that the connector portion 614 can be formed of a morerigid material while at least the wings 616 can be formed of a softermaterial. The softer wings 616 can improve comfort while the more rigidconnector 614 enables the buckle 602 to carry the loads that areexpected to be experienced in the headgear assembly 602.

In some configurations, the two or more different materials can beovermolded or comolded to form the buckle 602. In some configurations,the two or more different materials can be mechanically connected (e.g.,snapfit, keyed or the like) or can be joined by cohering, adhering, orthe like. In some configurations, at least the wings 616 can be formedof a thermoplastic elastomer or an impact-modified polyethylene, forexample but without limitation. In some configurations, the connectorportion 614 can be formed from a nylon or the like, for example butwithout limitation. In some configurations, the connector portion andthe wings can be formed from materials having the same base material(e.g., materials that have suitable chemical relationships to allowjoining of the materials).

With reference still to FIG. 62, the wings 616 preferably generallytaper in thickness from the region proximate the connector portion 614toward the lateral extents 616. While any suitable tapering profile canbe used, the reduction in thickness facilitates flexure of the wings 616to enable better conformity to the anatomy of the user. In other words,the reduced thickness of the wings 616 at locations laterally outwardfrom the portion adjoining the connector portion 614 results in a weakerflexural strength, which helps conformity to the anatomy of the user.

With reference again to FIG. 61, the wings 616 have side walls 622 thattaper inward. The inwardly tapering side walls 622 join to end walls 624with rounded corners 626 in the illustrated configuration. The roundedcorners 626 improve user comfort while the tapering side walls 622reduce the width of the wings 616. The reduced width of at least theends of the wings 616 facilitate capturing the wings 616 within thefolded regions of the straps 606 underneath the ends 608, which is bestshown in FIG. 59 and FIG. 60. In some configurations, the folded ends608 and/or the adjoining portion of the straps 606 define a pocket thatreceives the tapering ends of the wings 616. In some configurations, thestraps 606 can widen in a region as discussed above. In the illustratedconfiguration, the connector portion 614 of the buckle 602 is wider thanat least a portion of the strap 606 such that the strap 606 can extendthrough the opening 612 defined in the connector portion 614 while thewings 616 taper such that the strap 606 can overlie and/or envelope thewings 616.

In some configurations, the wings 616 extend away from the connectorportion 604 a length L2 that is greater than twice the thickness L1 ofthe wall of the connector portion 604 defining the slot 612. Otherconfigurations also are possible. As discussed above, the extendedlength L2 of the wings 616 reduces flop over of the straps 606 whenconnected with the winged buckle 602. The wings 616 can have a length L2that is less than a length of the connector portion of the ends 608 suchthat lateral extents 618 of the wings 616 can be enveloped by theconnector portion of the ends 608.

Although the present invention has been described in terms of a certainembodiment, other embodiments apparent to those of ordinary skill in theart also are within the scope of this invention. Thus, various changesand modifications may be made without departing from the spirit andscope of the invention. For instance, various components may berepositioned as desired. Moreover, not all of the features, aspects andadvantages are necessarily required to practice the present invention.Accordingly, the scope of the present invention is intended to bedefined only by the claims that follow.

What is claimed is:
 1. An elbow assembly configured to connect a maskassembly to an air conduit, the elbow assembly comprising: an elbow anda sleeve, the elbow comprising inner and outer walls and defining an airflow channel therebetween, the inner wall having an inner surface and anouter surface, the outer wall having an inner surface and an outersurface, the inner surface of the outer wall spaced from the outersurface of the inner wall and the air flow channel defined between theinner surface of the outer wall and the outer surface of the inner wall,the inner wall comprising a port in fluid communication with the airflow channel, the elbow having a frontmost surface facing away from auser in use, a rearmost surface facing toward the user in use, a firstlateral side surface facing in a first lateral direction in use, and asecond lateral side surface facing in a second lateral direction in useopposite the first direction, each of the first and second lateral sidesurfaces extending between the frontmost surface and the rearmostsurface, the elbow comprising a first opening located in the firstlateral side surface and a second opening located in the second lateralside surface, each of the first and second openings defined between theouter surface of the inner wall and a lateral edge of the outer wall,the sleeve being coupled with the elbow, wherein the frontmost surfaceis defined by the outer surface of the inner wall and the rearmostsurface is defined by the outer surface of the outer wall; and a flap,wherein when the flap is at a first position, the flap at leastpartially blocks the port and allows gas from the air conduit to pass tothe user via the elbow, and when the flap is at a second position, theflap at least partially blocks the air conduit thereby allowing gas toflow from the user through the port into the air flow channel and thento a location outside of the elbow, wherein the air flow channel directsair out of the lateral side surfaces of the elbow relative to the userand away from the user.
 2. The elbow assembly of claim 1, wherein theair flow channel comprises two air flow channels.
 3. The elbow assemblyof claim 1, wherein the second opening is diametrically opposed to thefirst opening.
 4. The elbow assembly of claim 1, wherein the frontmostsurface extends across an entire width of the elbow.
 5. The elbowassembly of claim 1, wherein the rearmost surface extends across anentire width of the elbow.
 6. The elbow assembly of claim 1, wherein thefirst and second openings are located laterally outward oflaterally-outermost extents of a flow channel through the elbow definedby the inner surface of the inner wall.
 7. The elbow assembly of claim1, wherein the first and second openings extend vertically along alength of the first and second lateral side surfaces.
 8. The elbowassembly of claim 1, wherein the sleeve further comprises a bumpextending around an outer surface of the sleeve and a recess adjacent tothe bump.
 9. The elbow assembly of claim 8, wherein the bump and therecess are adapted to receive a swiveling component incorporating aridge to engage with the bump.
 10. An elbow assembly configured toconnect a mask assembly to an air conduit, the elbow assemblycomprising: an elbow and a sleeve, the elbow comprising inner and outerwalls and defining an air venting channel therebetween, the inner wallhaving an inner surface and an outer surface, the outer wall having aninner surface and an outer surface, the air venting channel definedbetween the inner surface of the outer wall and the outer surface of theinner wall, the inner surface of the inner wall defining a flow channelthrough the elbow from the air conduit to the mask assembly, the innerwall comprising a port located in a portion of the inner wall positionedtoward a user and between the flow channel and the user in use, the airventing channel in fluid communication with the flow channel via theport, the sleeve being coupled with the elbow; and a flap, wherein whenthe flap is at a first position, the flap at least partially blocks theport and allows gas from the air conduit to pass to the user via theflow channel through the elbow, and when the flap is at a secondposition, the flap at least partially blocks the flow channel therebyallowing gas to flow from the user to a location outside of the elbowassembly via the port and the air venting channel, wherein duringexhalation, gas flows from the flow channel toward the user through theport into the air venting channel, and changes direction from the portand flows out of the elbow assembly, wherein the air venting channeldirects air away from the user.
 11. The elbow assembly of claim 10,wherein the elbow comprises two openings at sides of the elbow that arein fluid communication with the air venting channel.
 12. The elbowassembly of claim 10, wherein the elbow comprises a recess and thesleeve comprises a flange, the flange secured within the recess.
 13. Theelbow assembly of claim 10, wherein the flap extends into the flowchannel from a base that is sandwiched between the elbow and the sleeve.14. The elbow assembly of claim 10, wherein in the second position, theflap pivots downward into contact with the sleeve to obstruct the flowchannel.
 15. The elbow assembly of claim 10, wherein in the firstposition the flap at least partially or completely covers the port. 16.The elbow assembly of claim 10, wherein the port extends through a wallof the elbow that comprises a generally planar inner wall.
 17. The elbowassembly of claim 10, wherein the elbow comprises one or more bias flowvent holes, wherein the bias flow vent holes are positioned in aforwardly directed orientation such that any bias flow does not directlyimpinge upon the user.
 18. The elbow assembly of claim 10, wherein thesleeve further comprises at least one bump extending around an outersurface of the sleeve and at least one recess adjacent to the bump. 19.The elbow assembly of claim 18, wherein the bump and the recess areadapted to receive a swiveling component, the swiveling componentcomprising a ridge on an inner surface of the swiveling componentconfigured to engage with the bump.
 20. The elbow assembly claim 18,wherein the sleeve comprises two or more recesses.
 21. The elbowassembly of claim 18, wherein the recess has a semicircularconfiguration and extends upward into the sleeve.
 22. The elbow assemblyof claim 18, wherein the sleeve comprises two or more bumps.
 23. Theelbow assembly of claim 18, wherein the at least one bump extends aroundan arc of about 70 degrees.
 24. The elbow assembly of claim 18, whereinthe at least one recess comprises at least two recesses and the at leastone bump is generally centered between two recesses.
 25. The elbowassembly of claim 10, wherein the elbow assembly comprises a swivel anda lever, the lever comprising a lower inwardly extending catch, and anupper portion of the swivel comprises a shoulder, the catch securing theswivel in an axial position on the sleeve by engaging with the shoulder,and wherein when an upper portion of the lever is depressed, the catchmoves away from the shoulder to allow the swivel to be removed from thesleeve.
 26. The elbow assembly of claim 25, wherein the lever overliesthe port such that the port is generally obscured from view.
 27. Theelbow assembly of claim 25, wherein the sleeve comprises a section thatextends outward to connect to the lever.
 28. The elbow assembly of claim27, wherein the sleeve and the lever are integrally formed.